Photographic printing process



Patented Feb. 2, 1932 UNITED STATES PATENT OFFICE GUSTAV KGGEL, OF KARLSRUHE, GERMANY -No Drawing. Application filed July 7, 1927, Serial No. 204,146, and in Germany July 7, 1926.

The present invention relates to a new photographic printing process, in which on a sensitive layer consisting of a colloid which contains a suitable non-fugitive organic substance situated on a suitable support such as glass, films, paper and the like, a picture is produced by exposing to photoactive rays a sensitive layer and subjecting it to the socalled physical development.

The sensitive layer employed in this process consists of a colloid such as gelatin, albumin, casein or colloidion, containing a non-fugitive organic substance adapted to receive energy from impulses transmitted by 5 visible or invisible photoactive rays and, if

colored, capable of being washed away easily by the further treatment. Such substances are organic compounds of all kinds, such as for example dye-studs and their intermedi ate products, such as amino compounds, hy-

droxy compounds, ketones and preferably diketo compounds of the anthraquinone series, and also organo-inorganic compounds, such as organic compounds of lead (ada ted in connection with lighting with X-raysg.

The physical development may be executed in a known manner, as for example by treating the layer with a metal salt, such as a silver or mercury salt, in the presence of a reducing agent. The metal. salt preferably is applied by impregnating the exposed layer with agnetal salt solution; in special cases the metal salt may be present in the photographic material before exposure.

For example, paper covered with a gelatin layer containing an anthraquinone derivative, such as a sulfonic acid, compound of anthraquinone, e. g, 2.7-disulfonie aeid derivative of anthraquinone, is exposed under a photographic negative, a weakly visible picture bein"; form-ed. Then it is immersed for a short time in a solution of'silver nitrate of 1 per cent. strength. Then follow a short treatment with 1-methylamino-4-hydroxy benzene developer acidified by acetic acid, a

short treatment with a solution of sodium thiosulfate, washing and drying.

A so produced picture may be further treated as usual in photography, that is to say it may be toned, bleached, tanned (for the bronie oil process) and then treated with watery or fatty ink.

In the claims the term sensitive is in tended to define compounds which are suitable to receive. energy from impulses by photoactive rays.

What I claim is:

l. The process which comprises subjecting a gelatin layer containing a sensitive nonfugitive organic substance to a printing process with photoactive rays and physically developing said layer.

The process which comprises subjecting a gelatin layer containing a sensitive nonfugitive substance derived from a hydrocarbon'to a printing process with photoactive rays and physically developing said layer.

3. The process which comprises subjecting f a gelatin layer containing a sensitive nonfugitive substance-derived from a hydrocarbon substituted by oxygen to a printing process with photoactive rays and physically developing said layer.

4. The process which comprises subjecting a protein layer containing a sensitive keto compound to a printing process with photo- 'active rays and physically developing said layer.

5. The process which comprises subjecting a protein layer containing a sensitive keto compound of the anthracene series to a printing process with photoactive rays and physically developing said layer.

6. The process which comprises subjecting a protein layer containing a sensitive compound of the anthraquinone series to a printing process with photoactive rays and physically developing said layer. 7. The process which, comprises subjecting a protein layer containing a sensitive sulfonated compound of the anthraquinone series to a printing process with photoactive rays and physically developing said layer.

8. The process which comprises subjecting a protein layer containing a sensitive disulfonic acid of the anthraquinone series to a printing process with photoactive rays and physically developing said layer.

9. The process which comprises subjecting a sensitive gelatin layer containing a sensitive disulfonic acid of the anthraquinone series to a printing process with photoactive v rays and physically developing said layer.

10. The process which comprises subject ing a sensitive gelatin layer containing 2.7 anthraquinone disulfonic acid, to a printing process with photoactive rays and physically developing said layer.

In testimony whereof, I afiix my signature.

GUSTAV KGGEL. 

